A radio apparatus, for example a cellular radio telephone intended for two-way communication, generally operates with either an external fixed rod or plate antenna, a retractable antenna, or with an internal antenna. The fixed rod or plate type of antenna has a predetermined length. Whilst such antennas can be relatively short, they are not conducive to a compact design nor are they particularly suitable for a radio intended to be carried in a pocket or other receptacle offering restricted space. In rod antennas, the elongate radiating element generally has a flexible construction so that it simply bends if it is subject to any force. Nevertheless, the antenna remains relatively vulnerable and it is a problem that the antenna is liable to break. This ordinarily necessitates replacing the whole antenna assembly including the (otherwise operative) impedance matching network, which can be relatively expensive. The position of the antenna also makes the telephone less compact and more difficult to stow away.
In EP-A-0036442 there is disclosed a personal radio transceiver in which a pivoted antenna is movable between an extended operating position and a retracted non-operating position, and, which, in the non-operating position, doubles as a pocket clip. In the operating position the antenna is connected to the antenna terminal of the transmitter and in the non-operating position, the antenna is connected to the antenna terminal of the receiver so as to enable the transceiver to receive radio signals. However, in order to transmit a radio signal, the antenna must be in the extended operating position which means the operator must extend the antenna for this with all the attendant problems of a conventional external rod antenna.